add tests

I'm adding a revocation test on wot pallet because it is only present in identity pallet and thus does not handle wot-related limitations.

Also adding identity validation cucumber test.

end2end-tests/cucumber-features/identity_creation.feature

@@ -6,7 +6,7 @@ Feature: Identity creation
     # - existential deposit (2 ĞD)
     # - transaction fees (below 1 ĞD)
     When alice sends 6 ĞD to dave
-    When alice sends 6 ĞD to eve
+    When bob sends 6 ĞD to eve
     # alice last certification is counted from block zero
     # then next cert can be done after cert_period, which is 15
     When 15 block later
@@ -21,8 +21,5 @@ Feature: Identity creation
     Then dave should be certified by bob
     Then dave should be certified by charlie
     When 3 block later
-    # eve is not member, but has enough ĞD to pay extrinsic fees
-    # I don't understand why she can not validate dave's identity 
-    # When eve validates dave identity
-    When alice validates dave identity
+    When eve validates dave identity
     Then dave identity should be validated